//
//
// bg_lib,c -- standard C library replacement routines used by code
// compiled for the virtual machine

#include "q_shared.h"

/*-
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)qsort.c	8.1 (Berkeley) 6/4/93";
#endif
static const char rcsid[] =
#endif /* LIBC_SCCS and not lint */

    typedef int		 cmp_t(const void *, const void *);

#ifndef min
#define min(a, b)	(a) < (b) ? a : b
#endif

/*
 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
 */
#define swapcode(TYPE, parmi, parmj, n) { 		\
	long i = (n) / sizeof (TYPE); 			\
	register TYPE *pi = (TYPE *) (parmi); 		\
	register TYPE *pj = (TYPE *) (parmj); 		\
	do { 						\
		register TYPE	t = *pi;		\
		*pi++ = *pj;				\
		*pj++ = t;				\
        } while (--i > 0);				\
}

#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
	es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;

static void swapfunc(char *a, char *b, int n, int swaptype)
{
    if(swaptype <= 1)
        swapcode(long, a, b, n)
        else
            swapcode(char, a, b, n)
        }

#define swap(a, b)					\
	if (swaptype == 0) {				\
		long t = *(long *)(a);			\
		*(long *)(a) = *(long *)(b);		\
		*(long *)(b) = t;			\
	} else						\
		swapfunc(a, b, es, swaptype)

#define vecswap(a, b, n) 	if ((n) > 0) swapfunc(a, b, n, swaptype)

static char *med3(char *a, char *b, char *c, cmp_t *cmp)
{
    return cmp(a, b) < 0 ?
           (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
                   :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
}

void qsort(void *a, size_t n, size_t es, cmp_t *cmp)
{
    char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
    int d, r, swaptype, swap_cnt;

    loop:
    SWAPINIT(a, es);
    swap_cnt = 0;
    if (n < 7)
    {
        for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
            for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
                    pl -= es)
                swap(pl, pl - es);
        return;
    }
    pm = (char *)a + (n / 2) * es;
    if (n > 7)
    {
        pl = (char *)a;
        pn = (char *)a + (n - 1) * es;
        if (n > 40)
        {
            d = (n / 8) * es;
            pl = med3(pl, pl + d, pl + 2 * d, cmp);
            pm = med3(pm - d, pm, pm + d, cmp);
            pn = med3(pn - 2 * d, pn - d, pn, cmp);
        }
        pm = med3(pl, pm, pn, cmp);
    }
    swap((char *)a, pm);
    pa = pb = (char *)a + es;

    pc = pd = (char *)a + (n - 1) * es;
    for (;;)
    {
        while (pb <= pc && (r = cmp(pb, a)) <= 0)
        {
            if (r == 0)
            {
                swap_cnt = 1;
                swap(pa, pb);
                pa += es;
            }
            pb += es;
        }
        while (pb <= pc && (r = cmp(pc, a)) >= 0)
        {
            if (r == 0)
            {
                swap_cnt = 1;
                swap(pc, pd);
                pd -= es;
            }
            pc -= es;
        }
        if (pb > pc)
            break;
        swap(pb, pc);
        swap_cnt = 1;
        pb += es;
        pc -= es;
    }
    if (swap_cnt == 0)
    {  /* Switch to insertion sort */
        for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
            for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
                    pl -= es)
                swap(pl, pl - es);
        return;
    }

    pn = (char *)a + n * es;
    r = min(pa - (char *)a, pb - pa);
    vecswap((char *)a, pb - r, r);
    r = min((unsigned int)(pd - pc), (unsigned int)(pn - pd - es));
    vecswap(pb, pn - r, r);
    if ((unsigned int)(r = pb - pa) > es)
        qsort(a, r / es, es, cmp);
    if ((unsigned int)(r = pd - pc) > es)
    {
        /* Iterate rather than recurse to save stack space */
        a = pn - r;
        n = r / es;
        goto loop;
    }
    /*		qsort(pn - r, r / es, es, cmp);*/
}

//==================================================================================

void *memmove( void *dest, const void *src, size_t count )
{
    unsigned int i;

    if ( dest > src )
    {
        for ( i = count-1 ; i >= 0 ; i-- )
        {
            ((char *)dest)[i] = ((char *)src)[i];
        }
    }
    else
    {
        for ( i = 0 ; i < count ; i++ )
        {
            ((char *)dest)[i] = ((char *)src)[i];
        }
    }
    return dest;
}

static int randSeed = 0;

void srand( unsigned seed )
{
    randSeed = seed;
}

int rand( void )
{
    randSeed = (69069 * randSeed + 1);
    return randSeed & 0x7fff;
}

#if 0
double atof( const char *string )
{
    float sign;
    float value;
    int		c;


    // skip whitespace
    while ( *string <= ' ' )
    {
        if ( !*string )
        {
            return 0;
        }
        string++;
    }

    // check sign
    switch ( *string )
    {
    case '+':
        string++;
        sign = 1;
        break;
    case '-':
        string++;
        sign = -1;
        break;
    default:
        sign = 1;
        break;
    }

    // read digits
    value = 0;
    c = string[0];
    if ( c != '.' )
    {
        do
        {
            c = *string++;
            if ( c < '0' || c > '9' )
            {
                break;
            }
            c -= '0';
            value = value * 10 + c;
        }
        while ( 1 );
    }
    else
    {
        string++;
    }

    // check for decimal point
    if ( c == '.' )
    {
        double fraction;

        fraction = 0.1;
        do
        {
            c = *string++;
            if ( c < '0' || c > '9' )
            {
                break;
            }
            c -= '0';
            value += c * fraction;
            fraction *= 0.1;
        }
        while ( 1 );

    }

    // not handling 10e10 notation...

    return value * sign;
}
#endif

double _atof( const char **stringPtr )
{
    const char	*string;
    float sign;
    float value;
    int		c = '0'; // bk001211 - uninitialized use possible

    string = *stringPtr;

    // skip whitespace
    while ( *string <= ' ' )
    {
        if ( !*string )
        {
            *stringPtr = string;
            return 0;
        }
        string++;
    }

    // check sign
    switch ( *string )
    {
    case '+':
        string++;
        sign = 1;
        break;
    case '-':
        string++;
        sign = -1;
        break;
    default:
        sign = 1;
        break;
    }

    // read digits
    value = 0;
    if ( string[0] != '.' )
    {
        do
        {
            c = *string++;
            if ( c < '0' || c > '9' )
            {
                break;
            }
            c -= '0';
            value = value * 10 + c;
        }
        while ( 1 );
    }

    // check for decimal point
    if ( c == '.' )
    {
        double fraction;

        fraction = 0.1;
        do
        {
            c = *string++;
            if ( c < '0' || c > '9' )
            {
                break;
            }
            c -= '0';
            value += c * fraction;
            fraction *= 0.1;
        }
        while ( 1 );

    }

    // not handling 10e10 notation...
    *stringPtr = string;

    return value * sign;
}
